Antennas for pocket telephones are usually comprised of an antenna rod with a length of a half or a quarter of a wavelength.
The half wave antenna has a current distribution in the form of half of a sine wave, that is the current is zero at the ends and has a maximum in the middle. This antenna type works well from a technical point of view, but it has the drawback that it is bulky. This is because at the usually used radio frequencies of 900 MHz a wavelength of approximately 30 cm is obtained. This means an antenna length of approximately 15 cm, which by many users is considered unpractical and implies a risk that the antenna will be damaged when the pocket telephone is used.
A quarter wave antenna is half as long, that is 7-8 cm, and is therefore more practical. However, this antenna type has an unfavourable current distribution in the form of a quarter of a sine wave, the current being zero at the top of the antenna and at a maximum at the antenna base.
Furthermore, a circularly polarized antenna comprising an elongated base portion and an essentially circular top loop that is perpendicular thereto is known per se from "Antennas", John D. Kraus, McGraw-Hill.
An object of the present invention is to provide a linearly polarized miniature antenna that in addition to being short also provides an essentially rectangular current distribution between the point of connection at the antenna base and the antenna top.